Re: Pb with use of redefined "=" operator

[Robert A Duff <bobduff@world.std.com>]

Matthew Heaney <matthew_heaney@acm.org> writes:

> Why would anyone complain about using a component that always works?

Because it's too slow?

Maybe it's no big deal for your stack example -- maybe the stack needs
100 words, and the tag field makes it 101.  But suppose the abstraction
were "point-in-a-plane" or "complex", where the thing needs two words of
useful data -- in that case, adding a tag field is a huge space
inefficiency.  And don't tell me memory is cheap -- it takes time to
initialize it, and it can wreck your caching behavior, which costs time,
and time is *not* cheap.

> We are not philosophers debating morality -- we are systems builders.
> Our goal is to build correct systems, by whatever means necessary.
> 
> If using a language feature to make an abstraction work is "gratuitous,"
> or seems like a "trick," then that is a telling observation of the
> language itself!

Yes, the language has a flaw.

- Bob
-- 
Change robert to bob to get my real email address.  Sorry.